With an ecommerce website, can the Many-Per-Click Conversions be trusted to show a correct total of sales made during the 30 days following a first click. What if a buyer bookmarks my order success page and then later visits it directly three times after a purchase has been made? Will analytics show four conversions under Many-Per-Click when only one sale has been made?
E-commerce site is a online sailing and purchasing sites its mean these sites make a business through out site. like some people come E-commerce site and purchase some items like mobiles laptops and others
You can trust the numbers. There's no reason not to. Not saying there can't be technical issues once in a blue moon but you can trust them. One conversion is tracked. It will be given to the appropriate visitor session no matter how many times they came back. Wouldn't make sense otherwise.
Usually people don't come too often to their order success page. They just start using the service you offered them and that's it. So yeah, if someone comes back many times to your e-commerce site and let's say that he purchases something on the 11th time (and assuming you've got enough data ie 500 people have gone through this process already of coming back after a first visit), then yes, you can trust your Many-Per-Click numbers, no issue there.